code: def explore_null() -> List[None]:
      """Return possible parameter values for the `null` parameter type (i.e. [None])"""
      return [None]
  
file_path: ludwig/ludwig/config_sampling/parameter_sampling.py
imports: import random
  from typing import Any, Dict, List, Union
  from ludwig.schema.metadata.parameter_metadata import ExpectedImpact
label_desc: Use image node_id 7 for calling a global function with example usage: explore_null() and returns: list